1. Field of the Invention
Exemplary embodiments relate to an image sensor module and an imaging device including the image sensor module, and a method of manufacturing the image sensor module and the imaging device, and more particularly, to an image sensor module including a wafer level chip size package, and a method of manufacturing the image sensor module, and an imaging device including the above image sensor module and a method of manufacturing the imaging device.
2. Description of the Related Art
As processing and packaging technologies for semiconductor devices have rapidly developed in recent times, solid state imaging devices, a kind of a photo-electronic device, usually require higher capacity with lower power consumption together with high degree of integration.
In the conventional solid state imaging device, a plurality of photodiodes may be arranged in 1-dimension or 2-dimensions. A plurality of photoelectrons are generated from the photodiodes responsive to external photo signals, and the photoelectrons are detected by an image sensor module. The image sensor module generates analogue image signals from the detected photoelectrons, and the analogue image signals are transformed to digital image signals in the solid state imaging device. Thus, the solid state imaging device may be classified as a charge-coupled device (CCD) type and a complementary metal oxide semiconductor (CMOS) type in accordance with the structure of the image sensor module.
Recently, CMOS image sensors (CIS) have been used in imaging devices more widely than the CCD image sensor, since the CIS has the significant advantages of lower power consumption and a higher degree of integration as the striking technological improvement of semiconductor devices. Thus, the CIS has been widely used in mobile devices such as a cellular phone, which particularly need low power consumption characteristics, and special equipments such as a surveillance camera and a biometric system, which particularly need high capacity and a high degree of integration.
A CIS chip is usually manufactured at a high degree of integration by utilizing process technologies for semiconductor devices, and is packaged into a CIS module by various packaging technologies. The CIS module may be applied to various electronic appliances with ease. However, recent electronic appliances, particularly mobile devices, require product characteristics of lightness, thinness, shortness and smallness, and thus the CIS module needs to be made smaller as much as possible. A chip size packaging (CSP) technology has been most widely used for making the CIS module as small as possible.
According to the conventional CSP technology, an image sensor chip, which is manufactured on a semiconductor substrate by a series of semiconductor manufacturing processes, is mounted on a transparent board such as a glass board in such a way that an electrode pad of the image sensor chip is electrically connected to metal wirings in the transparent board by an external terminals such as a solder ball. In addition, the image sensor chip and the transparent board are also mechanically bonded to each other by the solder ball, thereby forming a CIS package. Particularly, the bonding of the image sensor chip and the transparent board is performed at a wafer level to simplify the packaging process and efficiently downsize the CIS package. A wafer, on which a plurality of the image sensor chips are manufactured, and the transparent board are bonded to each other as a whole, and the assembly of the wafer and the transparent board is then cut into pieces by an image sensor chip. That is, the image sensor packages are obtained by cutting the assembly of the wafer and the transparent board into pieces, not by bonding an individual image sensor chip to the mounting substrate.
A camera lens is combined with the individual image sensor chip to thereby form a wafer level image sensor module. Then, the image sensor module is installed to an inside of a metal housing for protecting the image sensor module from surroundings, thereby manufacturing a miniature solid state imaging device.
The camera lens is adhered onto the transparent board of the image sensor package by an adhesion material or substance. Consequently, the metal housing protects the image sensor module only from external shocks, and thus the image sensor module may still be damaged by vapor in environmental air.
The vapor in the environmental air can freely flow through the metal housing and cause damage to the image sensor module in the metal housing. In addition, the vapor in the adhesion material is also vaporized in the metal housing and causes damage to the image sensor module.
Particularly, when the imaging device is operated for a long time, or under humid atmospheric conditions, the vapor in the environmental air is condensed on a surface of the camera lens in the metal housing. The condensation of the vapor on the camera lens seriously deteriorates the image quality of the imaging device.
Accordingly, there is still a need for an improved wafer level image sensor module or an imaging device including the improved image sensor module in which the vapor in an environmental air and the adhesion can be efficiently removed.